The present invention is directed generally to a cap assembly, and more particularly to a protector cap for providing a positive sterility seal over the port of a pharmaceutical container.
Fluids intended for intravenous administration, such as nutrient solutions and blood, must be sterile at the time of use to avoid the danger of introducing harmful agents into the body. This requires not only that the container and its contents be in a sterile sealed condition at the time of receipt by the user, but also that no contamination of the contents occur when the container is opened by a physician or medical technician prior to use. The problem of maintaining sterility is particularly acute at the port of the container where the container wall is punctured by the point of the cannula of an administration set or other flow system to allow removal of the fluid, since the danger exists that contamination accumulated on the container housing during transport or storage may be introduced by the cannula into the container.
To guard against this it has become common practice to provide a protective cap over the container port, which ordinarily consists of a thin puncturable wall portion in the housing through which the cannula is inserted, and a cylindrical molded neck portion protruding from around the wall portion on which the cap is seated. The neck portion includes a central passageway and provides protection for the wall portion as well as a seat for the cap. The cap remains in place until the time of use, when it is removed from the neck portion and the cannula is inserted through the underlying wall portion to withdraw the fluid in the container for use.
One problem with this arrangement had been the necessity of tightly affixing the protective cap to prevent its falling off during transit or storage. This has made the caps difficult to remove, particularly under the emergency conditions and in the unfavorable environments where patients must often be treated. Even the most effective seal arrangement becomes unsatisfactory and potentially dangerous when it is excessively difficult or time-consuming to remove, since attention may have to be diverted from the patient undergoing treatment.
Another problem with such cap assemblies has been the impossibility of determining whether the sterile condition in the container port has in fact been maintained. Should the protective cap become loose or fall off in transit, and be subsequently replaced or tightened, the danger exists that the neck portion of the port may harbor contamination which can be carried by the cannula into the solution being adminstered. Another problem with prior art protector caps is that as they were initially installed on a container neck portion they caused air to be trapped and compressed within the neck portion. When the container was subsequently heat-sterilized in an autoclave, the compressed air expanded and, being trapped, loosened or blew off the caps.
Accordingly, the present invention is generally directed to a new and improved protector cap for maintaining a seal at the port of a fluid container.
The invention is further directed to a new and improved cap for maintaining a vacuum over the puncturable membrane portion of the port of a fluid container.
The invention is further directed to a new and improved protector cap for the port of a fluid container which is not subject to being forced off by trapped air during subsequent heat-sterilization.